Isotope: element variations with different atomic mass but same atomic number Isotopic Abundance: the relative amount in which each isotope of an element Calculating: given 2 isotopes of an element [B: 10.01u] [B: 11.01u] 1) Given average atomic mass: 10.81u If given percentages‚ you can find average atomic mass by adding each portion 2) Set variables for unknown values Let x represent % abundance for 10/5 B Let 1-x represent % abundance for 11/5 B Calculate: 10.01x+(1-x)11.01=10.81 10.01x+11.01-11
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(2) (b) A gas oil fraction from the distillation of crude oil contains hydrocarbons in the C15 to C19 range. These hydrocarbons can be cracked by strong heating. (i) Write the molecular formula for the alkane with 19 carbon atoms. (ii) Name the type of reaction involved in cracking. (iii) Write an equation for one possible cracking reaction of the alkane C16H34 when the products include ethene and propene in the molar ratio 2:1 and only one other compound. (4) (Total 6 marks) 2. A compound
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following questions. ___e___ 1. A hypothesis is a(n) a. formulation of principles based on facts. b. modification of a theory. c. organized body of knowledge. d. tentative explanation of observations. e. None of the above. __b___ 2. The initial success of the Bohr theory was based on a. its ability to predict the atomic spectra of multi-electron atoms. b. its ability to predict the atomic spectrum of hydrogen atoms. c. its prediction of the precise radius of electron
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During the electrolysis of molten lead bromide‚ which of the following takes place : A : Bromine is released at the cathode. B: Lead is deposited at the anode. C : Bromine ions gain electrons. D: Lead is deposited at the cathode. Ans : - D. Q. 2. Here is an electrode reaction : Cu → Cu2+ + 2e-. [i.e. Cu- 2e- →Cu2+]. At which electrode(anode or cathode) would such a reaction take place. Is this an example of oxidation or reduction. Ans : - At anode. Oxidation. Q. 3. A solution contains magnesium
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when it cooks is also a chemical reaction (if this does not happen the bread will have not have shape) Baking powder: Baking powder has two chemical reactions which are the following: 1. When it is mixed with wet ingredients it reacts to add co2 2. But that is not all when it hits the oven it reacts to the heat as well. Double Replacement: Baking soda (NaHCO3) reacts with acidic substances (HA) in cake batter in a double replacement reaction: Reactant Product NaHCO3 + HA
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Figure 1 shows the average amount of absorbance for each tube‚ containing different levels of pH. Tube 2 had an acidic pH level‚ Tube 3 had a neutral pH level‚ and Tube 4 had a basic pH level. It is indicated that the absorbance rates were the highest for the neutral pH level‚ with a final absorbance rate of 0.166. This was followed by a basic pH (0.106). The acidic pH level had the least amount of absorbance with a final absorbance rate of 0.069. This reinforces the idea that the ALP enzyme worked
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Objectives The main objective of this experiment is to differentiate between a physical change and a chemical change. A physical change includes a change in the material without affecting its composition‚ such as the physical state change. However‚ a chemical change includes the change in the composition of the substance. The change in color‚ formation of a gas or a solid product‚ and the production of energy are the evidences of a chemical reaction‚ thus‚ of a chemical change. Materials
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solution NaOH is a very corrosive chemical and contact with it can cause burns to body tissue and possible eye damage. Can irriate the lungs and can cause permanent lung damage. also contact with water can generate enought heat to ignite combustibles. 2. In your own words‚ briefly explain the terms below. Copied answers will receive zero points. a. equilibrium state When a chemical reaction is equal. when the products and reactients are at equal rates b. the effect of formation of a complex a complex
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Chapter 16 Notes The heart lies in the mediastinum and is surrounded by a doubled layered membrane called the pericardium. The outer most layer of the pericardium is called the fibrous pericardium‚ which anchors the heart to surrounding structures. The inner layer is called the serous pericardium and is composed of two layers. The outer portion is called the parietal pericardium‚ the inner portion is called the visceral pericardium (epicardium). Epicardium- outer most layer of the heart wall
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Neutral Basic NaCl KNO3 NaOH HC2H3O2 Na2CO3 NaC2H3O2 NaHCO3 Fe(NO3)3 NaNO3 Na3PO4 HCl MgSO4 KOH HNO3 Na2SO4 NaHPO4 CuSO4 NaNO2 CoCl2 Al(NO3)3 NiCl2 H2SO4 KCl NH4Cl 12. CuSO4 CuCO3.Cu(OH)2(s) + 2 H2SO4(aq) ----> 2 CuSO4(aq) + CO2(g) + 3 H2O(l) Na3PO4 Na3PO4 (aq) + 3H2O (l) --> H3PO4 (aq) + 3NaOH (aq) 13. Arrhenius definition says that a base yields the hydroxide ion (OH-) in an aqueous solution. Arrhenius definition is dependent on substances
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